2023.4.13

 1 //c++语言程序设计第二章习题
 2 //2-24
 3 #include <iostream>
 4 using namespace std;
 5 int main()
 6 {
 7     Flag:
 8     cout<<"现在正在下雨吗？是（Y）否（N）"<<endl;
 9     char c;
10     cin>>c;
11     if(c == 'Y')
12         cout<<"现在正在下雨"<<endl;
13     else if(c == 'N')
14         cout<<"现在没有下雨"<<endl;
15     else
16         goto Flag;
17     return 0;
18 }

 1 //c++语言程序设计第二章习题
 2 //2-25
 3 #include <iostream>
 4 using namespace std;
 5 int main()
 6 {
 7     int score;
 8     cout<<"你考试考了多少分？（0~100）"<<endl;
 9     cin>>score;
10     if(score>=90&&score<=100)
11         cout<<"优"<<endl;
12     if(score>=80&&score<90)
13         cout<<"良"<<endl;
14     if(score>=60&&score<80)
15         cout<<"中"<<endl;
16     if(score>=0&&score<60)
17         cout<<"差"<<endl;
18     return 0;
19 }

 1 //c++语言程序设计第二章习题
 2 //2-26
 3 #include <iostream>
 4 using namespace std;
 5 int main()
 6 {
 7  Flag:
 8     char c;
 9     cout<<"Menu:A(dd)D(elete)S(ort)Q(uit),select one:"<<endl;
10     cin>>c;
11         switch(c)
12         {
13             case 'A':cout<<"数据已经增加"<<endl;
14                 break;
15             case 'D':cout<<"数据已经删除"<<endl;
16                 break;
17             case 'S':cout<<"数据已经排序"<<endl;
18                 break;
19             case 'Q':break;
20         }
21         if(c != 'Q')
22         {
23             goto Flag;
24         }
25     return 0;
26 }

//c++语言程序设计第二章习题
//2-27
#include <iostream>
using namespace std;
int main()
{
    for(int i = 2;i<=100;i++)
    {
        for(int j = 2;j<=i;j++)
        {
            if(i%j == 0&&i!=j)
                break;
            if(i == j)
                cout<<i<<"\t";
        }
    }
    return 0;
}